Willow Lake:

Photographed by: Brian Herbelin ( Click on image to be directed to his webpage)

Willow Lake is a popular Southern Oregon reservoir, which stores the waters of Willow Creek, a tributary of the South Fork of Big Butte Creek. It is commonly known as Willow Creek Reservoir and this name appears routinely on maps. The 52-foot high, earth fill dam was completed in 1952 by the Medford Water Commission to store water as part of their municipal water system. Other uses are for irrigation and recreation. The contributing drainage basin is primarily within the Rogue River National Forest and drains the west slopes of Mt. McLoughlin. However, there are many sections of privately owned land within the National Forest boundaries. The lake itself is on county land, which has been developed by Jackson County as the Willow Lake Recreation Area. It includes facilities for camping and picnicking as well as a paved boat ramp. A small, private resort is also located on the shore. Willow Lake is heavily fished; kokanee were stocked about 1960 and have produced very well. Rainbow and cutthroat trout are also found, although in lesser numbers.

Willow Creek was dammed in the 1950's to provide summer irrigation
flow. The lake is used for recreation. Storage from this lake provides summer flow to
Willow Creek. Summer pre-reservoir stream discharge in Willow Creek during normal precipitation
years was very low (less than 1 cfs) downstream to near BBS where spring discharge
increased stream discharge.

Use of water from the Watershed is principally by diversion and export via the Medford Water Commision(MWC) pipeline system. Export by the MWC of water exiting as springs in the Big Butte Springs area began in 1927. In 1951 diversion was increased to the nominal maximum of 26.4 million gallons per day (40.9 cfs). A potential maximum of 36 million gallons per day (55.7 cfs) is possible using the existing diversion system. At times of lower demand the springs are allowed to overflow into Willow Creek to become part of the base flow. The Eagle Point Irrigation District diverts water from South Fork Big Butte Creek near Butte Falls. The State of Oregon Fish Hatchery just upstream from station no. 55 is operated using a "flow through system" and consumes very little stream flow. The system diverts and returns discharges ranging from 12 to 15.5 cfs. 4 - 6 Direct use of surface water within the Watershed for irrigation is by small diversions on Fourbit and Willow Creeks for pasture land. Some portion of these diversions return to the streams at downstream locations within the Watershed. A few shallow domestic wells are located at the downstream end of the Watershed, i.e., along Cook Road, at the Church Camp (Horse Creek area), and west of Big Butte Springs. This water volume was considered too low to be significant in the water balance calculations.

Willow Creek tributaries consist of the East and West Branches and Bieberstedt and Duel Creeks. Those tributaries now flow into Willow Lake. The East Branch is unique in that it flows over the young Bear Pan lava flow for most of its length. This narrow lava flow originated from 4 - 12 Mt. McLoughlin and continued down the East Branch and is interpreted to be in contact with the major valley-filling flows. It is through and near the base of the Bear Pan flow that groundwater is interpreted to contribute to the groundwater supply. The remainder of the groundwater from this basin is interpreted as contributed via infiltration and seepage through the YHC lavas downstream from the Willow Basin outlet upon which Willow Creek flows .

There are two stream gauging stations on Willow Creek, Station no. 53 located about 0.5 mile downstream from Willow Creek Dam and station no. 54 located farther downstream and west of the Medford Water Commision Big Butte Springs facility and about 2200 feet upstream from the junction with South Fork Big Butte Creek. The records from these stations are important because station no. 53 (Upper Willow) measures outflow from Willow Creek Basin (modified by the controlled discharge from Willow Lake) and because station no. 54 (Lower Willow) records the gain from springs into lower Willow Creek.